This invention relates to a hydraulic type starting clutch for use in an automatic transmission of infinitely variable speed type for automotive vehicles.
Conventionally, a starting clutch of this kind is known, e.g. from U.S. Pat. No. 3,171,524 which employs friction plates arranged to be urged against each other directly by a centrifugal force produced by a centrifugal governor. However, to obtain required transmission torque through this type clutch, the centrifugal governor has to be designed large in size. On the other hand, a conventional hydraulic type starting clutch, which is known, e.g. from U.S. Pat. No. 3,690,429, is constructed such that output pressure from an operating oil source per se is controlled to control the urging force applied to the friction plates, making the hydraulic pressure control system complicated in structure.